There is no point to have brilliant articles in your website if they are not read by anyone. Likewise, there is no point in having an excellent product or service if nobody buys it. It’s all about TARGETED TRAFFIC (mostly from search engines) => Visitor conversion => …and sales. That’s exactly why we all do search engine optimization. SEO efforts help us to rank our websites on Google which is the biggest traffic source anybody can have. In short, SEO is the lifeblood of any online business or website

Backlinks from other sites is the chief way that search engines determine a site's popularity and value, unfortunately their system is manipulated by bought links many from networks of sites made just for that purpose.

edu and gov domain name are only issued to institutions that can prove their qualification, making links from these sites somewhat more trustworthy and potentially better rank boosters. There are signs that abuse of student blogs at universities, etc. have damaged the value of edu links.